Perfluoroalkyl acrylate polymers and process of producing a latex thereof



United States Patent facturing Company, St. Paul, Minn., a corporationof Delaware No Drawing. Continuation of application Ser. No. 677,229,Aug. 9, 1957. This application Apr. 23, 1963,

Ser. No. 274,920

8 Claims. (Cl. 260-294?) ing these polymers can be represented by thegeneral formula:

wherein R is hydrogen or a methyl radical, R; is a perfiuoroalkyl grouphaving from 3 to 12 carbon atoms and m 18 an integer from 3 to 12.

It has been found that esters of terminally perfiuorinated alcohols inwhich a chain or bridge containing at least three methylene groups isinter-posed between the perfluoroalkyl tail and the hydroxyl grouppossess unusual properties. The acrylate and methacrylate esters ofthese alcohols can be polymerized to produce polymers which areparticularly suited for rendering cloth and other fibrous materials bothhydrophobic and oleophobic. Such alcohols are disclosed and claimed inthe application of one of us (Arthur H. Ahlbrecht), S.N. 247,357, filedDecember 26, 1962, as a continuation-in. part of the present applicationand of application S.N. 664,911, filed June 11, 1957.

The useful w-per-fluoroalkyl-substituted acrylate esters of theinvention can be produced by interreaction of the,

selected perfluoroalkyl alkanol and acrylic or methacrylic acid. Theintermediate perfluoroalkyl alkanols are prepared by reduction ofhalogenated perfiuoroalkyl alkanols produced by desulfonylative additionof perfiuoroallranesulfonyl chlorides to unsaturated alkanols such 'asallyl alcohol and homologs thereof, as shown in the following equations:

catalyst R SOC1 CH2=CH-CH:OH

Haney nickel, Hz,NaOH

Oither analogous addition reactions of perfiuoroalkanesulfonyl halidesto unsaturated esters and acids, as described in the copendingapplication of G. V. D. Tiers, S.N. 532,743, filed September 6, 1955,now Patent No. 2,965,659, followed by reductive dehydroh-alogenation,also lead to the intermediate perfluoroalkyl alkanols of the presentinvention, either by further saponification of the resulting esters orby reduction of the corresponding distally perfiuoroalkylated aliphaticacids or esters thereice v of using, for example, lithium aluminumhydride. These reactions are illustrated by the following equations:RiSOzCl OHz=CHCH2-CH20CO-CH3 RfCH2CHC1CH2C 2O-C O-CH Raney nickel, Halkalilz/ Raney nickel, H2, alkaliiz/ Suitableperfluoroalkyl-substituted alkanols for use in preparing the monomers ofthe invention are exemplified by 3-(perfluorooctyl)propanol,l2-(perfluorobuty1)dodecan-l-ol, 6-(perfluorodecyl)hexan-l-ol,5-(perfiuoropropyl)pentan-1-ol, 12-(perfluorododecyl)dodecan-Lol, 7-(perfluorooctyl)heptan-l-ol and the like. When esterified with acrylicacid or methacrylic acid, the acrylate and methacrylate esters,respectively, of the corresponding alcohols are obtained.

The monomers of the invention are readily polymerized by the methodsknown to the art, for example by bulk polymerization, solutionpolymerization and emulsion polymerization, using catalysts such asbenzoyl peroxide or other free radical polymerization initiators.

Preparation of polymers and vulcanized rubbers from such monomers is setforth more fully in the following specific examples which it is to beunderstood are for purposes of ilustration only. These polymers,including both homopolymers and copolymers prepared from these monomers,are characterized by the presence in the skeletal chain of repetitive orrecurring units which can be represented as follows:

wherein Rf, R and 111 have the significance set forth hereinabove. Thehomopolymer contains these repetitive units attached to one another bythe valence bonds shown unattached in the above formula; copolymers cancontain these groups interspersed with groups derived from ethylenicallyunsaturated monomers, for example, vinyl type monomers such as vinylchloride, vinyl stearate, styrene; butadiene; and the like. When fibersare coated with these homopolymers or with their copolymers theperfluoroalkyl tail is apparently preferentially exposed on the outersurface of the fiber, thereby imparting oil resistance and waterresistance to the fibers whether in the form of a woven fabric or cloth,or in the form of a random web as in paper or felt.

EXAMPLE 1 Preparation of 3-(Heptadecaflu0r00ctyl)-Pr0pyl Acrylate In aml. round bottomed flask fitted with thermometer well bearing athermometer and a reflux head comprising a 12 in. long by about /2"diameter fractionating column packed with glass helices and surmountedby a Barrett trap and reflux condenser were placed 35 g. of benzene, 0.3g. para-toluene sulfonic acid, 0.2 g. of hydroquinone, 2.88 g. (0.04mole) of acrylic acid and 19.1 g. (0.04 mole) ofB-(heptadecafluorooctyl)-propyl alcohol. The flask was heated at about82-83 C. so that the refluxing benzene carried water into the Barretttrap as rapidly as formed. After about 4 hours, a total of 0.72 ml. ofwater, approximately the theoretical amount, had collected and no moreappeared to be removed by the benzene vapors. Benzene was removed bydistillation until the temperature in the flask was about 95. Heatingwas then stopped and the remaining solvent was removed by application ofan aspirator with intermittent swirling and warming to avoid excessiveheating of the product. The residue was taken up in about 25 ml. ofether and washed first with 10% aqueous sodium hydroxide to removeunreacted acrylic acid and the toluenesulfonic acid and thereafter witha few cc. of water to remove alkali. The residue was transferred to aflask for vacuum distillation, about 0.1 g. of hydroquinone was addedand ether was removed under vacuum and the residue finally distilled at0.02 mm. pressure. The fraction boiling at 72-76 at 0.02 mm. pressureweighed 16.0 g. It Was dissolved in ether and filtered to remove a smallamount of polymer, washed with a small amount of 10% aqueous sodiumhydroxide to remove hydroquinone and evaporated to give a residue of12.5 g. of viscous, virtually colorless, low melting3-(heptadecafluorooctyl)-propyl acrylate having n =1.3421.

Calculated: C=31.5%;F=60.6%. Found: C=3l.3%; F=59.9%.

3-(heptadecafluorooctyl)-propyl acrylate was bulk polymerized by adding0.003 g. of benzoyl peroxide to 0.6 g. of monomer and heating at 50 C.for 2.5 hours. The polymer was a rather tough rubber.

Emulsion polymerization of 2 g. of 3-(heptadecafluorooctyl)-propylacrylate in 3.6 g. of 60:40 water:rnethanol using 0.1 g. potassium11-perfluorooctyl-hendecanoate as an emulsifier and 0.01 g. potassiumpersulfate as a catalyst at 50 for about 15 hours gave about 68%conversion to polymer. The resulting clear blue latex (Latex 1)contained no precoagulum. The polymer had an inherent viscosity in 1:2acetone-methyl perfluorobutyrate of 0.35.

A similar polymerization was carried out at 50 C. for about 17 hoursemploying g. of the above monomer in 9 g. of 70:30 water-acetone and0.25 g. of potassium N-ethyl-2-(perfluorooctane sulfonamido)-acetate asan emulsifier and 0.025 g. potassium persulfate as catalyst. The latex(Latex II) which formed was blue but slightly cloudy owing to a trace ofprecoagulum. The isolated polymer (82% conversion) was rubbery and hadan inherent viscosity in 1:2 acetone-methyl perfluorobutyrate of 0.40.

The two latices (hereinafter designated respectively I and II) thusprepared were tested as in treatments for both cotton and Visa cloth.Visa is the trade name of Deering-Milliken and Co., Inc. for a fabricconsisting of a blend of 45% wool and 55% polyethylene terephthalatefibers. Seven by seven inch squares of the respective cloths weretreated by padding thereon the respective emulsions diluted to 1% solidswith water so that about 1% of polymer (based on fabric weight) waspresent in the fabric. The four specimens thus obtained were driedminutes at 140 C. and tested for resistance to water and oil.

Hydrophobic properties of the treated cloth were determined by Method22-52 of the American Association of Textile Chemists and Colorists anddescribed, for example, on pages 136 to 138, inclusive, of the TechnicalManual and Yearbook of that association for the year 1954. It is to benoted that this method provides for no interpolation of results whichare reported as one of the Standard Spray Test ratings which are the sixratings 0, 50, 70, 80, 90 and 100.

Oleophobic properties were measured by means of ratings assigned on thebasis of resistance for 3 minutes to drops of oil-turpentine mixturesvarying by 10% increments from pure mineral oil (Nujol, Stanolind, etc.)to pure turpentine applied gently to the surface of the textilemaintained level and are indicated by numerals 0 to 10 respectively forthe mixture of highest turpentine content which fails to penetrate. Thusthe numeral 5 indicates a mixture of 50% of each of the two components.Interpolation is judged visually and indicated where significant bymeans of plus or minus signs.

The above specimens of fabric treated with the two latices were testedwith the results shown in Table I.

TABLE I Spray Oil Re- Latex Cloth rating pellency Rating Cotton 50 3-7Visa 10 Cotton.... 50 10 Visa 70 10 These repellency properties on Visaare not lost on repeated dry cleaning.

EXAMPLE 2 Preparation of 11-(Heptadccafluoro-Octyl)-Undecyl Acrylate andM ethacrylate This ester was prepared by substantially the procedureused in the preparation of its lower homolog in Example 1 from 15 g.(0.0254 mole) of the corresponding alcohol and 2 g. (0.028 mole) ofacrylic acid in the presence of 0.5 g. each of p-toluene sulfonic acidand hydroquinone, refluxing and distilling water from the reactionmixture into a Barrett trap over a period of about 6 hours. The cooledreaction mixture was diluted with ether, filtered to remove insolublematerial, and washed with 10% sodium hydroxide to remove acidic andphenolic materials. The organic solution was dried. Solvents wereremoved under vacuum to leave a residue of 12 g. of a solid ester havingthe expected composition as shown by infra-red absorption spectrum and amelting point of about 2836 C.

The methacrylate ester was prepared by a similar reaction using theequivalent amount of methacrylic acid. It was a tan, pasty solid meltingat about 2327 C.

Bulk polymerization of the acrylate ester gave a crosslinked polymer.Latices were prepared from the acrylate and methacrylate esters byemulsion polymerization using 5 g. of monomer in 9 g. of 70:30acetonezwater containing 0.25 g. of potassiumN-ethyl-2-(perfluorooctanesulfonarnido)-acetate as emulsifier and 0.025g. of potassium persulfate as a catalyst, by heating under a nitrogenatmosphere at 50 C. for about 16 hours with agitation. The latices wereslightly tan-colored with some precoagulum. The real conversion to thepolymers from the monomeric acrylate and methacrylate esters wererespectively 96% and 86% and inherent viscosities in 1:2 acetone-methylperfluorobutyrate were respectively 0.14 and 0.12.

The latices from the acrylate and methacrylate esters (hereinafterdesignated as Latex III and Latex IV respectively) were employed totreat cotton and Visa cloth by the method described in Example 1. Theresults of tests for water and oil resistance (performed as before onthe treated specimens are shown in Table 1 1).

TABLE II Spray Oil Re- Latex Cloth Rating pelleney Rating EXAMPLE 3Preparation of S-(Heptafluoro-Propyl)-Prpyl Acrylate This ester wasprepared by substantially the procedure used in the preparation of otheracrylates but using a greater excess of acrylic acid. A mixture of 9.0g. (0.04 mole) of the alcohol and 7.2 g. (0.1 mole) of acrylic acid in10 g. of benzene with 0.3 g. of p-toluene' sulfonic acid and 0.2 g. ofhydroquinone was refluxed and the water (about 0.8 ml.) collected in aBarrett trap for about 3 hours. The material was distilled to removebenzene and the residue taken up in ether and Washed first with 3%sodium hydroxide to remove excess acid, catalyst and hydroquinone andthen with water. The neutral ethereal solution was fractionallydistilled through a Vigreaux column equipped with heating mantle topromote more eflicient operation and, after initially removing eitherand a forerun boiling at 71-75 /10 mm., 9 grams of3-(heptafluoropropyl)-propyl acrylate were collected at 7576/ 10 mm.,which showed the expected infrared absorption maxima and had n -=1.3562.

Emulsion polymerization of 4 g. of this monomeric acrylate ester wascarried out in 7.2 g. of Water containing 0.13 g. of sodium laurylsulfate and .01 g. of potassium persulfate heated with agitation for 5hours at 50 C. followed by freezing to coagulate the polymer. The white,rubbery polymer was separated, washed and dried and had inherentviscosity in 2:1 acetonezmethyl perfluorobutyrate of 2.3. The rubber wascured by blending 100 parts of polymer with 6.72 parts of sodiumsilicate nonahydrate and 2.72 parts calcium hydroxide followed byheating at 310 F. in a press at 900 pounds pressure for 20 hours. Arubbery elastomer showing good resistance to oils was obtained, which,when prepared in sheet form, was useful for preparing gaskets, capliners and the like.

The cured rubber showed a flexing resistance tenfold that at roomtemperature (T of 11 as determined by ASTM Procedure D1053-54T. It wastested for solvent resistance by ASTM Procedure ED471-54T and showed thefollowing:

Solvent: Volume percent swell Acetone 250 Benzene 65 70:30isooctaneztoluene 65 Dioctyl sebacate hydraulic fluid (penola oil) 15Preparation of 3-(Heptaflu0ropropyl) -Pr0pyl Methacrylate Into around-bottomed flask fitted with stirrer, dropping funnel and refluxcondenser and resting in an ice bath were placed 200 cc. of anhydrousdiethyl ether, 10.1 g. (0.10 mole) of triethylamine and 22.8 g. (0.10mole) of 3-(heptafluoro propyl)-propyl alcohol. The mixture was stirredand cooled to about 5 to 10 C. and 10.4 g. (0.10 mole) of methacrylylchloride were added slowly over about ten minutes. About 0.2 g. ofhydroquinone was added to act as a polymerization retarder and the flaskwas stoppered and allowed to stand overnight (about 18 hours). Themixture was worked up by adding 200 cc. water to dissolve theprecipitated triethylamine hydrochloride and the ether layer wasseparated, and distilled under reduced pressure. The lower layer of theresidue remaining weighed 27 g. It Was distilled under reduced pressurein a conventional vacuum distillation apparatus to give two fractions,the second of which was 3-(heptafiuoro propyl)-propyl methacrylate,

boiling point 70-73 C./ 10 mm.; n =1.3636. The yield was 15.5 g. Found:C, 40.2%; F, 45.0%. Calculated: C, 40.5%; F, 45.0%.

Emulsion polymerization of this monomer was effected using 100 parts ofmonomer in 180 parts of water containing 5 parts of dodecylaminehydrochloride as emulsifier and 0.5 part of potassium persulfate as acatalyst, with shaking for about 15 hours at 50 C. The bluish latex thusobtained was employed at 1% polymer solid concentration for thetreatment of samples of cotton and Visa cloth as above. The treatedcloths rated for water repellency. Treated Visa cloth showed significantoil repellency.

EXAMPLE 5 Preparation of 5-(Heptadecaflu0r00clyl)-Pentyl Methacrylate.5-(heptadecafluorooctyl)-pentanol (prepared by reaction ofperfluorooctanesulfonyl chloride and pent-4-en- 1-ol in the presence ofditertiary butyl peroxide and subsequent catalytic dehydrohalogenation)was esterified with methacrylic acid by the procedure described inExample 4. The S-(heptadecafluorooctyl)-pentyl methacrylate thusprepared was distilled and found to boil at 102104/ 0.1 mm. pressure.

Found: C, 35.3%; F, 55.7%. Calculated: C, 35.6%; F, 56.3%.

This monomer was emulsion-polymerized by heating at 50 C. for 17 hours amixture of parts of monomer, 126 parts of water, 54 parts of acetone,0.5 part of potassium persulfate and 5 parts of potassiumN-ethyl-2(perfluorooct-anesulfon am-ido)-acetate as an emulsifier. Theclear blue latex contained some precoagulum and 34.0% polymer solids.The inherent viscosity of the polymer in 1:2 acetone-methylperfluorobutyrate was 1.06 at 25 C.

The latex was diluted to 1% polymer solids and employed as above intreating cloth. The treated cloth was dried for 10 minutes at 140 C. andrated for water repellency. The rating for oil repellency was based onfailure of penetration of mixtures of mineral oil and heptane for 3minutes. The ratings corresponding to the various percentages of heptaneare:

A similar latex prepared using dodecyl trimethyl ammonium chloride asthe emulsifier showed substantially similar results but was lesseffective in conferring water repellency.

Intermediate alcohols employed till the preparation of the compounds ofthe invention are provided as follows:

EXAMPLE 6 A mixture of 26.8 g. (0.052 mole) of perfluorooctanesulfonylchloride and 5.0 g. (0.050 mole) of 4-pentenoic acid (allyl-acetie acid)is refluxed for four hours at about 145 C. in the presence of acatalytic amount (1.0 g.) of di-terti-ary butyl peroxide The reactionmixture is fractionally distilled under reduced pressure and thefraction boiling at about 100 C. at 0.01 mm. is collected. Afterrecrystallization from a mixture of chloroform and carbon 'bisulflde,the 4-chloro-5-(perfluorooctyl) pentanoic acid thus prepared melts atabout 89-90 C.

The 4-chloro-5-(perfluorooctyl)-pentanoic acid thus prepared ishydrogenated by shaking a solution of 8.00 g. (0.0145 mole) of the acidand 2.5 g. (0.062 mole) of sodium hydroxide in a mixture of 30 ml. ofwater and 30 ml. ethanol for 3 hours at 140 C. in a rockinghigh-pressure hydrogenation apparatus, in the presence of 4 g. of Raneynickel catalyst and with hydrogen supplied at 2500 p.s.i. pressure.After removal of the catalyst and evaporation to dryness, an amorphousresidue is obtained comprising sodium S-(perfluorooctyl)-pentauoate. Bydissolving this residue in water followed by acidification of theresulting solution, the saturated perfluoroalkyl aliphatic acid formedby hydrogenation is recovered as a waxy white solid, which can bedistilled at 100 C. at 0.02 mm. pressure. After recrystallization fromcarbon bisulfide, the S-(perfiuorooctyl)-pentanoic acid thus preparedmelts at about 86.587.3 C. The procedure described in U.S. Patent2,666,797, using lithium aluminum hydride, is employed for reduction ofthe acids to the corresponding alcohols. A suspension in ether of 30parts of 5-(perfluorooctyl) pentanoic acid is added to a solution of 3parts of lithium aluminum hydride in about 200 parts of anhydrous ether.The reaction mixture is stirred for about 48 hours and then is treatedwith water and neutraliZed with sulfuric acid. The reaction mixture isextracted several times with ether, and the ether extracts are combined,dried and fractionally distilled in vacuo. There is obtained5-(perfluorooctyl)-pentanol boiling at about 108 C. at 2.5 mm. pressureof mercury.

In the same way, using IO-undecenoic acid in preparation of theperfiuoro acid instead of allyl-acetic acid, there is produced11-(perfluorooctyl)-undecanoic acid, which on reduction yieldsll-(perfiuorooctyl)-undecanol boiling at about 122126 C. at 0.10-0.15mm. pressure of mercury.

By repeating the foregoing procedure, employingperfluoro-n-pentanesulfonyl chloride and perfluorododecanesulfonylchloride (prepared by the process of Brice et a1. as disclosed in U.S.Patent No. 2,732,398) instead of perfluorooctanesulfonyl chloride, thereare obtained, respectively, S-(perfluoropentyl)-pentanoic acid andS-(perfiuorododecyl)-pentanoic acid. Likewise, when 3-butenoic acid,6-heptenoic acid and IO-hendecenoic acid are employed instead of4-pentenoic acid in carrying out the procedure of this example, thereare obtained, respectively, the corresponding 4-(perfiuoroocty'l)butyric :acid, 7- (perfluorooctyl)-heptanoic acid andll-(perfiuorooctyl) hendecanoic acid. Upon reduction, these acids yieldthe corresponding S-(perfiuoropentyl) pentanol,5-(perfluorododecyl)-pentanol, 4-(pei fiuorooctyl)-butanol,7-(perfluorooctyl)-l1eptanol and 11-(perfluorooctyl)-hendecanol,respectively.

Perfluoroalkyl-substituted propanols can be prepared by the methodexemplified as follows: to a mixture of 80 g. of perfluorooctyl sulfonylchloride and 31 g. of allyl acetate are added about 3 g. of di-tertiarybutyl peroxide and the reaction mixture is slowly heated to about 80 C.,whereupon a spontaneous rise in temperature to about 130 C. occurs.After this reaction is over there is added a further amount of thedi-tertiary butyl peroxide. Heating is continued for about 14 hours atabout 110 C. with a further addition of peroxide after about 8 hours ofheating. The reaction mixture is then fractionally distilled in vacuo,and the 2-chloro-3-(perfiuorooctyl) allyl acetate which is formed in thereaction is recovered, as a fraction boiling at about 153158 C. at 37mm. pressure. To a solution of 50.5 g. of this substance in 50 ml. ofanhydrous methanol containing phenolphthalein indicator is addedslightly more than the theoretical amount of sodium methylate inmethanol solution. The reaction mixture becomes slightly pink and sodiumchloride is precipitated. After standing about 48 hours at roomtemperature, the reaction mixture is treated with about ml. of water andan additional amount of sodium methylate, and then warmed to about 50 C.for about 4 hours. The organic phase is then removed and fractionallydistilled, the fraction boiling over the range 129-141 C. at 37 mm.pressure of mercury being recovered. The S-(perfluorooctyl) allylalcohol thus prepared has index of refraction n =1,3328. A mixture of 42g. of 3-(perfluorooctyl) allyl alcohol, 1.8 g. of Raney nickel, 45 m1.of ethanol and 1 g. of potassium hydroxide is charged to an autoclaveand hydrogen under about 150 atmospheres pressure is introduced.Hydrogenation to the corresponding saturated alcohol takes place asevidenced by a drop in pressure over a period of about an hour. Thecontents of the autoclave are removed, filtered and the filtrate isfractionally distilled in vacuo. There is obtained3-(perlluorooctyl)-propanol, which boils at about 138-143 C. at 38 mm.pressure and has index of refraction n =1.3312. The infra-redspectrogram of this substance indicates that it is completely saturated.

3-(perfluoropropyl)-propanol is prepared starting with ethylperfiuorobutyrate as follows: Approximately equimolar quantities ofethyl perfluorobutyrate, methyl acetate and sodium methoxide are used.The ethyl perfluorobutyrate is added to a cooled solution of sodiummethoxide in absolute ether, with continued cooling. After stirring thismixture for approximately two hours the methyl acetate is added,whereupon a clear solution forms. The solution is stirred forapproximately 16 hours and then fractionally distilled under reducedpressure, to remove solvents and to obtain methyl 3-(perfiuoropropyl)-3-keto propionate as the main product. The keto-ester thus obtained ishydrogenated under pressure with Raney nickel catalyst, in ethersolution, under the usual conditions, for about two hours. The catalystis removed by filtration and the filtrate is fractionally distilled invacuo, where- 'upon methyl-3-(perfiuoropropyl)-3-hydroxy propionate isrecovered, boiling at about C. at 15 mm. pressure and having refractiveindex n =1.3513. About 157 parts of the hydroxy ester thus obtained and175 parts of phosphorous pentoxide are mixed and allowed to stand forapproximately 16 hours (a rather strong exothermic reaction being notedshortly after mixing). The reaction mixture is then filtered and thefiltrate is purified by fractional distillation. There is obtainedmethyl-3-(pcrfiuoropropyl) acrylate which boils at 12l124 C. at 732 mm.pressure and has refractive index n =1.3362. The acrylic ester ishydrogenated in ether solution using Raney nickel catalyst and highpressure under the usual conditions. The reaction mixture is filteredand the filtrate is fractionally distilled under reduced pressure. Thereis obtained the corresponding saturated ester, methyl3-(perfluoropropyl) propionate, which boils at 42 C. at 12 min. pressureand has refractive index n =1.3276. To a solution of 7.6 g. (.2 mole) oflithium aluminum hydride in 500 ml. of ether are added 49 g. (0.191mole) of the methyl-3-(heptafluoropropyl)propionate dissolved in ml. ofether; at such a rate that vigorous refluxing is maintained. The mixtureis then stirred for 1 hour and an excess of methanol is added tohydrolyze the complex. The reaction mixture is next acidified withdilute sulfuric acid. The ether layer is separated and the aqueous layeris further extracted with about an equal volume of ether. The combinedether phases are evaporated to remove the ether and the residue isfractionally distilled. The 3-(heptafluoropropy l)-propanol thusobtained boils at about 141 C. at 745 mm. pressure and has index ofrefraction n =1.3270.

What is claimed is:

1. Polymers having a skeletal chain containing recurring perfluoroalkyl:acrylate ester units represented by the formula:

Fla

wherein R is a member of the group consisting of hydrogen and the methylradical, Rf is a perfluoroalkyl radical having from 3 to 12 carbon atomsand m is an integer from 3 to 12.

2. A process for the preparation of a fluorocarbon polymer whichcomprises polymerizing in the presence of an effective amount of freeradical generating catalyst a perfluoroalkyl-alkyl acrylate having theformula:

wherein R is a member of the group consisting of hydrogen and methyl, Ris a per fluoroalkyl radical having from 3 to 12 carbon atoms and m isan integer from 3 to 12, in an aqueous vehicle.

3. A process for producing a polymeric latex from a monomer which may berepresented -by the formula:

wherein R is a member of the group consisting of hydrogen and methyl, Ris a perfluoroalkyl radical having from 3 to 12 carbon atoms and m is aninteger from 3 to 12, which comprises agitating an aqueous mediumcontaining said monomer in dispersed form together with a Watersolublefree radial initiator and an emulsifying agent, until an amount of themonomer is polymerized.

4. A polymer according to claim 1 wherein R is hydrogen, R is C F andmis 3.

5. A polymer according to claim 1 wherein R is hydrogen, R; is C8F17 andm is 3.

6. An aqueous latex suitable for rendering fibrous materials oilrepellent, containing a polymer having a skeletal chain containingrecurring perlluoroalkyl acrylate ester units represented by theformula:

10 wherein R is a member of the group consisting of hydrogen and themethyl radical, R is a perfluoroalkyl radical having from 3 to 12 carbonatoms and m is an integer from 3 to 12.

7. A textile fabric which has been sized with an aqueous latexcontaining a polymer having a skeletal chain containing recurringperfluoroalkyl acrylate ester units represented by the formula:

wherein R is a member of the group consisting of hydrogen and the methylradical, R is a perfluoroalkyl radical having from 3 to 12 carbon atomsand m is an integer from 3 to 12, so as to have been rendered oilrepellent.

References Cited in the file of this patent UNITED STATES PATENTSAhlbrecht et a1. June 16, 1953 'ORear Apr. 15, 1958

1. POLYMERS HAVING A SKETAL CHAIN CONTAINING RECURRING PERFLUOROALKYLACYLATE ESTER UNITS REPRESENTED BY THE FORMULA*